Ibandronate: its role in metastatic breast cancer

Bisphosphonates are the most effective agents for treating and/or preventing complications of bone metastases and are the standard of care in this setting. Currently, four bisphosphonates are available for metastatic bone disease (MBD): clodronate, pamidronate, zoledronic acid, and ibandronate. Although all four of these bisphosphonates have been shown to reduce the incidence of skeletal-related events in patients with bone metastases, there are substantial differences among these agents in their potency, dose and route of administration, and side effects. Ibandronate and zoledronic acid, the two newer aminobisphosphonates, appear to have similar biochemical efficacies when phase III trial data are compared. Both agents were equally effective in reducing markers of bone resorption in the only prospective comparative trial carried out to date, but no data on relative clinical efficacy are available from head-to-head comparisons. Both the oral and i.v. formulations of ibandronate have also shown long-term efficacy in managing metastatic bone pain (MBP), but the onset of action of standard bisphosphonate treatment is not sufficient when rapid relief of pain is required. Because of its favorable renal safety profile, i.v. ibandronate can be administered daily for 3 days, as a so-called "loading dose." This dosing regimen has allowed rapid and effective relief of MBP without the unwanted side effects associated with opioids and other analgesics. Ibandronate is thus an effective, flexible, and well-tolerated bisphosphonate that can meet the varying requirements of patients with MBD.